Some Heating Does Not e.g. Top Floor
Some Reasons A floor or two can be without heating, usually upper floors;
Response to a client with the above question;
If the head of is insufficient to remove all air then there are two distinct potential issues;
1) There are parts of the system outside the hydraulic gradient if so they would have never worked and there is a design error.
2) There is an unknown issue of a closed valve somewhere, such as a motorised valve. In the case of a motorised valve, this would be a control issue, this is all much more likely to be the case if the issue was not present in the past.
If radiators or towel rails work only once after being cleaned if so it was only when there were filled with heated water and they never actually circulated.
I've also see lock shields left closed after installation as there is a least one common brand which leaves the factory in the closed position and not everyone checks they are open, not often but worth checking.
There could be a gradual build-up of oxides in the system that has added sufficient resistance to cause the system to fail at the upper levels, (though ideally a system should be designed in such a way that it can still operate in these conditions). Changing the system from gravity to pumped or if already pumped from open to sealed will significantly improve pressure and flow reducing the impact of resistance. A flush can help a design change is more effective.
Another possibility is that there is a pump that has failed or is air locked. If a pump cannot be found it may be concealed a check of the wiring will confirm if a pump is present or not and if there is power going to the pump. If there is no power to the pump then there is a control issue. The towel rails failing gradually issues matches up with a pump wearing out, which is a given every 10 years or so.
Finally, there could be an airlock, this could also build up gradually install the air is a restriction to flow, a partial blockage until air builds up. Although commonly known as an airlock is probably a buildup of hydrogen gas following rusting or other oxidation processes leading to a breakdown of water as the oxygen bonds with iron or aluminum. Airlock can be cleared by putting mains water directly into the system or pumping water in.
We have a lot of experience with complex problem solving and work in a significant amount of large domestic as well as commercial properties.
CULKIN PLUMBING AND HEATING LTD
Director JEFF CULKIN ACIPHE RP RHP
29B CHANDOS ROAD
Gas Safe Reg no 305929
Company No. 07980305
VAT No. GB172932986
D-U-N-S Number: 21-827-8135
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